tests/resource/aws_cognito_user_pool_client: Ensure name update test failure without fix
tests/resource/aws_cognito_user_pool_client: Ensure name update test failure without fix

Updated test before code fix:

```
--- FAIL: TestAccAWSCognitoUserPoolClient_Name (22.23s)
    testing.go:568: Step 1 error: Check failed: 1 error occurred:
        	* Check 2/2 error: aws_cognito_user_pool_client.test: Attribute 'name' expected "name2", got "name1"
```

Output from acceptance testing:

```
--- PASS: TestAccAWSCognitoUserPoolClient_basic (15.26s)
--- PASS: TestAccAWSCognitoUserPoolClient_importBasic (17.08s)
--- PASS: TestAccAWSCognitoUserPoolClient_allFields (18.60s)
--- PASS: TestAccAWSCognitoUserPoolClient_RefreshTokenValidity (24.41s)
--- PASS: TestAccAWSCognitoUserPoolClient_Name (24.48s)
--- PASS: TestAccAWSCognitoUserPoolClient_allFieldsUpdatingOneField (24.57s)
```

kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,terraform-providers/terraform-provider-aws